Pulverized coal feeder



W. D. WO0D.

PULVERIZED COAL FEEDER.

APPLICATION man SEPT. 2:. 191a.

Patented Dec. 9, 1919.

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PULVERIZED COAL FEEDER.

APPLICATION FILED SEPT. 2!. ma.

Patented Dec. 9, 1919.

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PULVERIZED COAL FEEDER.

APPLICATION FILED SEPT. 27, I918.

1,324,366. Patented Dec. 9,1919.

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PULVERIZED COAL FEEDER.

APPLICATION FILED SEPT. 21, 191a.

Patented Dec. 9,1919.

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entrain srA PATENT orrrorf WALTER DONGAN WOOD, OF .ALLENTOIVN, PENNSYLVANIA, ASSIGNOR TO FUEL SAVING COMPANY, OF ALLENTOIVN, PENNSYLVANIA, A CORYORATION OF PENNSYLVANIA.

PuLvnmzED-ooAL FEEDER.

Specification of Letters Patent.

Patented Dec. 9, 19.19,

Application filed September 27, 1918. Serial No. 255,938.

To all whomrit may concern:

Be it known that I, WALTER DONGAN VVooD, residing at Allentown, in the county of Lehigh, State of Pennsylvania, have invented certain new and useful Improvements in Pulverized-Coal Feeders; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to apparatus particularly adapted for feeding pulverized fuel from a supply chamber to a combustion chamber.

Many types of apparatus have been devised for this purpose and in most of them screw conveyors are employed for feeding the pulverized fuel from a source of supply to a point where an air blast conveys the fuel to the furnace, the air blast also providing the oxygen necessary to support combustion. IIoretoforo it has been the practice to mount each of the screw conveyors within a separate passageway or hopper, even when a number of such conveyors were used. Such an arrangement possesses the disadvantage that the fuel tends to become packed or arched overv the individual conveyors, particularly when the apparatus is used upon a vehicle such as a locomotive, thus stopping the feed of fuel, and when the fuel is finally released it is emitted with a rush, producing the so-called flooding action with consequent variations in combustion.

The present invention has for an object the avoidance of this defect of prior constructions by an arrangement of the screw conveyors in pairs with the conveyors of each pair placed closely adjacent and parallel to each other within a common passageway leading from the source of fuel supply. The conveyors of each pair are rotated in unison, and preferably in opposite directions, by suitable driving means such as an engine, clutch mechanism being provided whereby the conveyors may be connected at will to the engine which may be suitably controlled as to speed. For transferring the pulverized fuel from the conveyors to the point where combustion is to take place, as well as for supplying the necessary oxygen to support combustion, the present invention provides means for supplying an air blast about the forward ends of the conveyors, and this means is provided with a controlling device which preferably is so connected to the clutch mechanism for connecting the convoyers to the engine, that when the conveyors are inoperative the air blast will be cut off.

Each pair of conveyors with its controlling devices and means for supplying an air blast constitutes a unit, and in practice any suitable number of such units may be employed. In the particular embodiment of the invention to be hereinafter described, there are two such units adapted to be driven from a common engine placed between them. The air blast is supplied from a blower mounted above the engine and provided with branching conduits leading to the two pairs of conveyors, each conduit having a damper connected to the clutch mechanism that controls the operation of the corresponding conveyor. By virtue of this arrangement the entire apparatus forms a compact unitary construction which can be easily secured in place adjacent: the source of fuel supply. 1

In the present case the apparatus of the invention is shown as applied to a locomotive, but it will be understood that it is equally applicable to any furnace in which pulverized fuel is to be burned. a

In the drawings, Figure 1 is an olevatio of a part of a locomotive and its tender showing the apparatus of the invention in place; Fig. 2 is a front elevation of the ap paratus; Fig. 3 is a side elevation; Fig. 4 is a plan view; Fig. 5 is a transverse section along the line 5-5 of 4;; and Fig. 6 is a section through the bottom of a part of the fuel supply hopper showing the relation of the conveyors thereto.

In the drawings, in which similar reference characters denote similar parts throughout the several views, 1 represents the locomotive and 2 the tender. The tendor carries a bin or tank 3 for holding pulverized fuel, and as shown in broken lines in Fig, 2, the bottom of the bin is given the form of two hoppers 4 each having sloping sides and at the bottom of which the fuel conveyors are placed.

The apparatus comprises two casings 5 each provided with flanges 6 for attachment to the front wall 7 of the fuel bin or tank. The casings are also provided with brackets 8 attached to a base 9 mounted upon the deck 10 of the tender. As an additional means for holding the apparatus i p diagonal braces 11 may be provided. Within each casing 5 is a pair of closely adjacent screw conveyers 12 which extend through the hoppers at of the fuel bin and are supported in bearings 13 at or near the rear wall of the bin. The flights of the conveyers preferably terminate at the points 12 where, near its outer end, each casing 5 is formed with an enlargement it having the shape shown most clearly in Figs. i and 5, and each enlargement is provided with internal partitions or deflectors 15 partly surrounding the shafts and having oppositely inclined inner faces 16. The upper end of each enlargement is provided with a flange to which is connected a conduit 17 leading to an apparatus for producing an air blast. In order that both pairs of conveyers may be supplied with an air blast from a common source, their respective conduits 17 are branched from a manifold 18 leading to fan or blower adapted to be driven from a small steam turbine 19 supported upon brackets 20 attached to the blower and additionally supported by a column 21 attached to a suitable bracket formed on corresponding casing 5. suitable construction, but is here shown as of the plate type adapted to be supplied with steam by a pipe 22 leading to the cab of the locomotive, where it is provided with a. valve 23 by which the speed of the turbine and blower may be controlled.

The bottom of each enlargement 14s is pro vided with a flange 24k to which is attached a pipe 25 adapted to have connected to its free end a flexible tube 26 leading to a suitable burner 27 at the fire-box 28 of the locomotive.

For driving the conveyers, a small steam engine 29 of any suitable construction is mounted upon a web 30 extending between the two casings 5. The shaft 31 of the engine carries at its forward end a pinion 32 meshing with a pair of gears 33 each loosely mounted on the shaft of one of the conveyers 12 of each pair. Associated with each gear 33 is a clutch member 3i, and slidably mounted on the shaft of the corresponding conveyer is a cooperating member 35 of the clutch, which may be operated by a lever 36 mounted on the outer end of a bracket 37 suitably attached to the top of the casing within which the screw conveyers are placed. For the purpose of driving the second screw conveyor of each pair, a gear 33 is attached to the shaft of the screw conveyor upon which the clutch member 35 is mounted, and this gear 38 engages a corresponding gear 39 on the shaft of the other screw conveyer.

Each of the air supply conduits 17 is provided with a damper 4:0 and these dampers are provided with external operating'arms 41 which are connected by rods 42 to the corresponding clutch operating levers 36, the

The turbine may be of any arrangement being such that when the levers are in position to disengage the clutch memhere, the arms 41 will be turned into position to place the dampers transversely of their conduits to cut Off the air blast from the corresponding pair of conveyers.

The engine is supplied with steam from the locomotive boiler through a pipe as which should preferably be provided with a controlling valve in the locomotive cab. It is desirable that the speed of the engine be closely regulated in order to prevent variations in the feed of fuel by the conveyers. For this purpose a governor 45 of any suitable construction may be employed. The governor may be driven by a belt or chain l6 passing over a suitable pulley or sprocket 47 attached to the rear end of shaft 31. WVhile the engine may be controlled by the valve (is in the cab, it is advisable to provide means for a more accurate control than can be obtained by the valve. F or thi purpose there is provided a flexible shaft 18 leading from a hand wheel L9 in the cab and connected to a shaft 50 beneath the deck of the tender. The shaft 50 is red to the lower end of a vert'cal shaft 51 which at its upper end is geared to a horizontal shaft 52, so connected to the governor 45 that the setting of the latter may be changed to produce a close adjustment of the steam supply for the engine, it being understood that for any given setting of the governor, the latter will act to maintain the speed the engine SUlJStZUb tially constant.

It is desirable that means be provided for indicating in the cab of the locomotive the speed of the engine or the rate of feed of the fuel. For this purpose there is provided in the locomotive cab a tachometer which is operated by a small magneto 53 mounted on the casing of the apparatus and driven by a chain 5 1 passing over a wheel 55 on the engine shaft 31.

In using the apparatus described above, the bin or tank of the tender is filled with pulverized fuel, and owing to the hopperlike construction of the bottom of the bin each pair of conveyers will be supplied with fuel so long as there is any in the bin. The driving engine and also the turbine will usually be in operation continuously, and the conveyers may be operatively connected to the engine as desired by shifting the clutch members 35 into engagement with the members associated with the gear wheels that are driven directly from the engine shaft. WVhenever the conveyer which has associated therewith the'clutch 35 is operatively connected to the engine, the other conveyer of the same pair will be rotated in a reverse direction by gears 38 and 39.

Whenever either or both pairs of con veyers are operatively connected to the en the corresponding dampers 10 will be rap open to permit an air blast to be supplied are two streams, as it were, of pulverized fuel issuing from each side of each feeder unit,and these two streams of fuel are both surrounded by a current of air and another current of air is blown in between them, so that the fuel is very thoroughly mingled with the air and broken up before it is blown into the furnace, thus insuring most effective combustion. By arranging the conveyers of each pair closely adjacent, the tendency for the fuel to arch over the screws is prevented, so that a much more uniform feed of fuel can be obtained at all rates of feeding, and the flooding action common to apparatus of this character, in which the conveyers are operated singly, is avoided. The apparatus is accordingly particularly adapted for use on locomotives fired with pulverized coal, where the vibrations tend to pack the coal and thus increase its liability to become arched over the conveyers if individual ones are used.

It has been found in practice that there may be a tendency for fuel to feed from one conveyer to the other within the bottom of the bin, so that but one of the conveyers is effective in feeding the fuel through the casing to the air blast. To avoid any such tendency, a partition 56 may be placed along the bottom of the bin between the two conveyers, and this partition should preferably extend at least as high as the top of the conveyers as shown most clearly in Fig. 6.

What I claim is:

1. In apparatus for feeding pulverized fuel, the combination of a casing, a number of closely adjacent parallel screw conveyers rotatably mounted within the casing and means for supplying an air blast about the forward ends of the conveyers to carry fuel, therefrom.

2. In apparatus for feeding pulverized fuel, the combination of a number of closely adjacent parallel screw conveyers adapted to act in unison upon a mass of fuel to convey the same forwardly and prevent packing and arching of the fuel during its travel. and means for supplying an air blast about the forward ends of the conveyers to carry fuel therefrom.

3. In apparatus for feeding pulverized fuel, the combination of a casing, a pan of closely adjacent parallel screw conveyers mounted within the casing, means for rotating said conveyers in unison in opposite directions and means for supplying an air blast about the forward ends of the con veyers to carry fuel therefrom.

-'l. In apparatus for feeding pulverized fuel, thecombination of a casing, a pair of closely adjacent parallel screw conveyers rotatably mounted within the casing, an engine, a pinion connected to the shaft of the engine, a gear loosely mounted on one of said conveyers, a clutch associated with. the same conveyer for operatively connecting the conveyer to the gear, a gear fixed on the same conveyer, and a gear on the other conveyer engaging the gear fixed on the first conveyer whereby said conveyers may be rotated in unison when said first-named gear is connected to the first-named conveyer by said clutch.

5. In apparatus for feeding pulverized fuel from a supply chamber. the combination of a casing mounted on the evterior of the chamber, a pair of screw conveyers disposed closely adjacent and parallel. to each other within the casing and extending within and along the bottom of the chamber, means for rotating said conveyers in unison to draw fuel from the chamber, and means for supplying an air blast about the forward ends of the conveyers to carry fuel therefrom.

In apparatus for feedihgpulverized fuel. the combination of a casing, a number of closely adjacent parallel screw conveyers rotatably mounted within the casing, means for supplying an air blast about the forward endsof the conveyers to carry fuel therefrom and means for controlling the air blast.

7. In apparatus for feeding pulverized fuel, the combination of a pair of closely adjacent screw conveyers, driving means for said conveyers, means for connecting said conveyers to said driving means at will, means for supplying an air blast about the forward ends of the conveyers to carry fuel therefrom, means for controlling the air blast, and an operating connection between said air blast controlling means and said conveyer connecting means so arranged that the air blast will be cut off when the conveyers are disconnected from the driving means.

8. In apparatus for feeding pulverized fuel, the combination of a casing provided with an enlargement, a pair of screw conveyers rotatably mounted within the casing and closely adjacent to each other, means for supplying an air blast through the enlargement of the casing, and partitions within the enlargement of the casing so arranged to directthe air blast between said conveyers and around the outside of the same to carry fuel therefrom.

9. In apparatus for feeding pulverized fuel, the combination of a casing provided with an enlargement, a pair of closely adjacent screw conveyers rotatably mounted within the casing with their shafts extending through the enlargement, means for rotating said conveyers, means for supplying an air blast through the enlargement, and partitions within the enlargement, said partitions being provided with oppositely directed inclined faces to direct the air blast between the shafts, and curved portions partly surrounding the shafts to deflect the air blast around the outside of the same.

10. In apparatus for feeding pulverized fuel from a supply chamber to a furnace, the combination of a number of closely adj acent parallel screw conveyers for carrying fuel from the chamber and means for supplying an air blast about the forward ends of the conveyers to carry fuel from the conveyers to the furnace and provide the air necessary for combustion when the mixture of fuel and air reaches the furnace.

11. In apparatus for feeding pulverized fuel, the combination of a plurality of pairs spondin-g-pair of conveyers to the driving means so arranged that when the conveyers are disconnected from the driving means,

the air blast to saidconveyers will be cut off.

12. In apparatus for feeding pulverized fuel, the combination of two pairs of closely adjacent screw conveyers, an engine mounted between the two pairs of conveyers, a speed controller for said engine adapted to be operated from a distance, clutch mechanism associated with each pair of conveyers for operatively connecting the same to the engine, a turbine driven blower mounted above the engine and provided with a manifold, separate conduits leading from the manifold to each pair of screw conveyers, a damper in each conduit, and operative connections between each damper and the clutch mechanism of the corresponding pair of conveyers so arranged that when the conveyers are disconnected from the engine, the

corresponding damper will be closed to cut off the air blast.

13. In apparatus for feeding pulverized fuel, the combination of a casing provided with an enlargement, a number of screw conreyers rotatably mounted within the casing and closely adjacent to each other, means for supplying an air blast through the enlargement of the casing and means within the enlargement of the casing for directing the air blast between and around the con veyers to carry fuel therefrom.

In testimony whereof I aflix my signature. I

WALTER DONGAN W'O'OD. 

